1. Field of the Invention
The invention relates generally to a device which is mounted inside the cover of standard electric utility meters for the purpose of preventing energy diversion by means of meter tampering. When a meter tamper event is sensed, the device discharges a brilliant flash of light and changes the appearance of a larger indelible indicator, informing both the would-be tamperer and the meter reader that an attempt has been made to divert energy.
Spiraling electricity costs have encouraged many otherwise honest consumers to attempt to divert energy by means of altering utility meter readings. It is estimated by several studies that energy diversion in the United States costs the electric utility industry in excess of one billion dollars annually in unaccountable losses. Such studies estimate that the average cost borne by each consumer amounts to between $20 and $40 per annum. Since the vast majority of energy diversion goes undetected, the actual magnitude of the problem is unknown.
Most electric utility meters in the United States are protected from meter tampering by small wire seals which are easily broken, reconfigured, counterfeited and/or replaced. Broken and reconfigured seals can be difficult if not impossible to detect in the course of normal meter reading procedures. More costly locked ring adapters which lock the meter to its receptacle provide a greater degree of protection, but the tools required for opening such devices are easily obtainable. Locked metal housings completely enclosing the meter which are used on many industrial consumers provide increased security, but are considered impractical in broadscale, residential applications.
2. DESCRIPTION OF PRIOR ART
Security systems have been the subject of many past inventions. There are numerous prior art devices which intended to prevent the theft of physical objects by triggering indicators or alarms when a suspicious event is sensed. One such alarm actuating device is found in U.S. Pat. No. 3,742,480. This device utilizes the breakage of a retainer wire wrapped around the hardware to be protected to trigger an audible and visible alarm circuit intended to attract immediate attention to the theft. The alarm circuit comprises a thermostatic lamp in combination with a battery operated electronic circuit to intermittently activate the lamp and an accompanying audible alarm. Other devices found in U.S. Pat. No. 3,289,194 and U.S. Pat. No. 3,423,747 are specifically intended to sound an audible alarm on the theft of household appliances by sensing the unauthorized act of unplugging the power cable from the wall outlet. These battery powered systems are designed to avoid false triggering in electrical power outages. In addition, a large number of electro-mechanical switch devices such as those found in U.S. Pat. Nos. 3,781,857; 4,365,240; 4,150,371; 4,047,167; 4,300,130 and 4,316,181 are intended to detect the removal or change in orientation of the protected equipment in order to trigger some associated security alarm system.
Although many such security systems are well known in prior art, it can be easily seen that securing against the unauthorized or unmetered flow of electricity is a generically different problem than securing a building or specific piece or equipment. For example, it is not only feasible but quite easy for a residential consumer to steal large amounts of electricity without ever removing the electric utility meter from its socket. If the meter is removed, it can easily be replaced by jumpers or modified to operate in reverse or at slower rates of registration. The problem is compounded by the fact that utility meters are located at long distances from the utility company and without substantial expense can not be monitored by central alarm systems. In addition, the large number of utility meters in a system requires the per meter expense of an effective energy diversion monitoring system to be quite low.
Serious disadvantages and shortcomings of prior art security devices prevent their direct adaptation to electric meter energy diversion. The vast majority of security devices would be too costly for broadscale application on residential electric meters. For example, most stand alone, electronic security systems require a battery power source for back up operation in power outages. However, batteries which operate in the extreme temperatures experienced inside an electric meter are quite expensive, and the expense associated with installation and replacement is prohibitive. In addition, many security systems seen in prior art such as that of U.S. Pat. No. 3,742,480 utilize continuous or intermittent audible and/or visible alarms to draw immediate attention to the theft. Although such techniques may be effective, they are impractical for energy diversion since the meter site is visited only once a month and any false alarms could cause severe problems.
While it would appear that the art disclosed in U.S. Pat. Nos. 3,289,194 and 3,423,747 would be adaptable to preventing the unauthorized unplugging of electric meters, similar shortcomings preclude their application in preventing energy diversion. First, the sensing method of detecting electrical disconnection alone is not adequate to detect the broad range of common meter tampering techniques. Second, the activation of local, continuous alarms serves no practical purpose. Finally, the required battery power source poses installation, maintenance and unit cost problems.
Although the multitude of security sensor switches of prior art may be adaptable to sense meter tamper events, any one of these switches alone would be insufficient to detect the wide range of common tampering methods. For example, the electro-mechanical switch and tamper indicator disclosed in U.S. Pat. No. 4,150,371 which is designed to sense the removal of a gas or water meter encoder device, could be adapted to sense the removal of an electric meter from its socket. However, such adaptation would require the modification of the meter and would not be effective in sensing meter tampering methods which do not require meter removal. Further, the tamper indicator disclosed provides only a very subtle indication which might be noticed by the meter reader but would not be obvious to the would-be thief. In such a case, the thief would proceed to divert energy at will.